Stereoscopic radio location device



Jan. 27, 1948. w. A. AYREs l STEROSCOPIC RADIO LOCATION DEVICE Filed 001.8, 1943 INVENTOR #Zapf/M4194 fly/ms Patented Jan. 27,` 1948 UNITED; STATES orsi i 2,434,897ff sclnaaosoorlo. RADIO LocATLoNYDEvIoE. WaldemarA. Ayres; Kew GardensHills;-N;- Y.. as signorto; Sperry Gyroscope-Cmpany,-Ii1c., a corporationl of-'New IYorlciL Applicatonetoberis, 1943Sferal No. 505,472. 22YClaims.. (C1.'2`5f0s11.62f)

This invention relates. generallyItostereoscopio apparatus, andspartioularly, concerns, stereosfopic apparatus, for directing an` instrument towarda selected. object...

stereoscopic.. apparatuseliasr heretofore been devised. Vfor providing. stereoscopic..representations ofobjieotsinga selectedlportiion ofspace.. The present inventiona is useful.';.ini. connection. with Such. apparatus providing a, stereoscopic representation `.ofal directional..characteristic .of an instrument. According to this., invention,I the stereoscopic representations of .the objects `and the .directional characteristic of v. the f instrument may be. Combined'. to ...shovv,. .stereosgzopioaliy,V the position .of `the., directionaL chaiacteristicA relative to ithe .positions ortho.. objects., `In thijsmanneria three-dimensional 4.picture is.for.med vin :the brain ofthe observer. Whichenabls him to maneuver the instrument .to ydirect. it toward. afselected` object...

The invention is particularly useful in anair traffic. control system. Forexamplaa-.three dimensional stereoscopic picture of theai`rcra-ft within' the 4 area. surrounding.. anairport maybe producedbv a radio. locator fand; appropriate dis. play device. In addition a stereoscopic repre.-` sentation` ofia communication ,b,eam.maybe.com. bined withV representationsof the aircraft. ena.- bling .an. operator to.- ,direct the. communication, beam toward aselected one of. the aircraftto give. specific" .instructions to.. that craft. llowever.,` air trafccontrolishut .one ,applicationoi the .inven-. tion. As willsbecome. apparent, vit y is also useful inj directing alli types. oflinstruments towardan obieot for any... purpose..4

It' is thereforea majorlobject. of ,the invention tov provide stereoscopicP` apparatusfor. directing an instrument toward a Selected object...

Another` object of the .l invention. .isto provide stereoscopic apparatusfor showing the positionv of a directional'characteristic of. an instrumentl relative to objects in a selected, areaorA portion-.of space,

A further. object of' .the invention isto produce a stereoscopic representation of a directional characteristic of an instrument.

A further object of the invention is to produce stereoscopic representations oiobjects andthe directional characteristic of an instrumentand combine theseV representations to form a composite stereoscopic representation ofthe position ofthe directional characteristic relative to the'po. sitionof .the object.,`

A further object oftheinvention viste; produce and combine stereoscopic representations of ob` 2.1:' jects overga selected'- area, an outline or image, of the area, and a directional characteristiciofA an instrument.

A further object oftheznventionA istoprovide apparatus for; directing a: communication instru` ment ./tovvardf.ar selected. object'A by providing stereoscopic*representations' ofitheV objects andA a, directionali characteristic.: .of the' instrument;

A', further object of' the invention -is to' provide ahnaratus' for, directing) a o0n1munoati0n-radio beam toward 'aselectedaircraft i A'stiillorther;object: of. the inventionis .torrovideapnaratusior directing.. arr instrument.. to-v Warda selectiedlobieotbr combining stereoscopic representations .of 'objects over.. a selrfsotecil area and" .offla directional; charact'eristi'e.ofY the instru-l mennandalso including anindioator.iorshowing the .displacement ofi the directional.. characteristic 4f rom a: selectedobieet..

OtherA objects and advantagesyror .theinvention will become apparent, from the.,follovving speci filiation taken ineonneotion with the axxiornna.nikA ins drawings wherein.;

Fig;z 1' .i'sxaY .schematic diagram of. stereoscopic apparatus. .embodying the invention, and.

Fig,2 isaperSpectiVe view ,showing a `preferredi' arrangement; of' the Aelements. forminga dispiayvdevice.. and shown... diaerainmatieaily in Fis.: 1.2.-..

The... `sneoiiiie..,.emloodimen-t of the` invention shown ....1 has. a radio locator iorrroduoing. stereoscopic.. representationsV of. .the soniometrieV position oigaircraftol other. objects Within ,a ser. iected portion .of space, anda picture generator foripliodueins stereosoopicv representations of. ,the soniometrioposition Vof .a communication .beam

pattern de ned 4Vby a directional. communi'ar.

tion antenna. .In .both yeases...the .stereosoonioxeffeet Vis'attained by. displacingv the. representation according .to .the distance. .of various..,obiects, .or portionsof' the. communication. .beam aboveI the ground.'

The representation .or the objects `and .the oommuni'cation. beam patternappear von a iluores-Y centfscreenof cathodeiray tubes ina display de vi'ce', If'j desired', stereoscopic `representations .of aniimage., .manor ,outlineor the ground area may becombined with'the other representations inA the display device.

One locator suitablefor producing stereoscopic representations ofV aircraftor other objects inca, selectedportion ofjspace iswshown diagrammatf icallyin' Eig; 1:r This locator consists ofl a direc.-v

tionalscanningradiator l I' that is'scanned;v over a selected portion of space in any'suitable manner. The particular form of scanner shown in the drawing is slowly oscillated in elevation about a horizontal axis by a motor I2 that drives through an eccentric I3, link I4, and lever I5 to oscillate shaft I6 that supports the antenna II, Shaft IS is journalled in a bracket I1 that is rotated at a comparatively rapid rate by a motor I 8 which drives through gear I9 to rotate gear 2i) on the bracket I'I in azimuth about a vertical axis.

The oscillating and rotating motions produced by these motors I2 and I 8 cause the beam pattern of the radiator II to spirally scan a selected portion of space. The radiator I I is supplied with high frequency radio energy from a transmitter '2| which is modulated by pulses of relatively short duration. The transmitter is connected through wave guides 22 and 23 to the scanner, which includes wave guides 24 and 25 together with the necessary rotating joints and couplings to permit scanning movements of the radiator II without disturbing the supply of radio energy thereto.

Energy reflected by objects within the portion of space scanned is collected by the antenna II and supplied through the wave guides to a receiver 27. The output of the receiver 21 is connected by lead 28 to intensity control grids 29 and V3| cf a pair of cathode ray tubes 32 and 33 which are elements of the display device which is viewed by the observer. The grids l29 and 3l are normally biased to cut 01T the electron flow in the tubes 32 and 33, but permit passage of theY beam upon the reception of radiant energy by the antenna II. The electron beams of tubes 32 and 33 are scanned over their respective screens 35 and 36 in a manner to be described, whereby the traces produced when grids 29 and 3| permit passage of the electron beams correspond to the goniometric position of objects reflecting energy to the antenna II.

Pulse modulation of the transmitter 2| is controlled by a synchronizer 33. The frequency of the synchronizer 38 determines the repetition rate of the transmitted pulses. The synchronizer 38 also may be connected to the receiver 21 in a manner rendering the receiver sensitive only during periods within which pulses of reflected energy are desired to be received by the antenna II.

The electron beams of the two cathode ray tubes 32 and V33 are deflected identically by sawtooth voltages applied to the deflecting plates by a sweep generator 4I at a rate corresponding to the frequency of the synchronizer 38. These sawtooth voltages are adjusted to cause the electron beams to sweep radially from the center of the screens of the tubes in a direction corresponding to an orthogonal projection of the antenna beam pattern to a horizontal plane at any instant.

The amplitudes of the sweeping voltages are further modified in accordance with the angular position of the antenna relative to a horizontal plane. In this manner the length of each radial sweep corresponds to the orthogonal projection of a beam pattern of finite length. The time of each radial sweep is controlled by the synchronizer 38 according to the repetition rate of transmitted pulses. Thus, the time is constant regardless of the length of the sweep. Therefore, the electron beams move more slowly during short sweeps than during longer ones. Y

voltages displaced by 90 degrees for rotating the electron beams in accordance with rotation of the antenna about the vertical axis I9 are produced by a two-phase generator 42 having twophase windings displaced by 90 degrees. The rotor of this generator is rotated in accordance with the azimuth spinning movements of the antenna II about a vertical axis by a shaft 43 that is driven by a gear 44 meshing with the gear 20. In order to determine the distance that the electron beams move during each radial sweep, the amplitudes of these two-phase voltages are varied according to the oscillating movements of the antenna in elevation.

This is accomplished by varying the eld strength of the generator 42 which is determined by the voltage output of a rotary transformer 48 driven by the shaft I6 according to the oscillations of the antenna II. The rotary transformer is energized from a suitable constant source 53 of alternating current. The output voltage of the rotary transformer 48 varies sinusoidally according to the elevation angle of the antennaJ II. This varying voltage is applied to the field winding of the two-phase generator 42.

The output voltages of the two-phase generator 42 depend upon the product of the voltages induced by the voltage applied to the eld winding and the voltage generated by rotation of the generator rotor in the magnetic field. As is well known, the multiplication of two sine wave voltages produces voltages having frequencies equal to the sum and difference of the frequencies of the two sine waves. These two sum and difference frequencies correspond to two side bands without a carrier.

In the present case, the multiplication of the induced and generated voltages in the two-phase windings results in voltages having sum and difference frequencies. However, the amplitudes of these voltages (the amplitude of the side bands) are varied in accordance with the elevation angle of the antenna. A suitable carrier may be inserted at this point by connecting the source 50 of alternating current voltage to the two-phase generator 42.

The output voltages of the two-phase generator 42 may be represented as a carrier modulated at the azimuth spin frequency and varied in amplitude according to the elevation angle. These voltages are similar, but are displaced by and are supplied as by leads 46 and 4l to sweep generator 4I where they are rectified. The envelopes of the rectified voltages are used to control the amplitudes of saw-tooth sweep voltages that are developed by the sweep generator 4I at a frequency determined by the synchronizer 38 to produce saw-tooth voltage waves at a frequency corresponding to the frequency of the transmitted pulses. This saw-tooth sweep voltage generator 4I is of such design that it may have either positive or negative voltage outputs depending upon the polarity of the control voltages. Furthermore, the amplitudes of the saw-tooth voltages are varied in accordance with the magnitude of the control voltages.

One output voltage of the sweep generator 4I is supplied by the lead 5I to vertical amplifiers 53 and 54 which are connected to vertical deflecting electrodes 55, 56, 57 and 58 of the tubes 32 and 33, respectively. The other output voltage is connected by lead 52 to horizontal ampliers 39 and 6I which are connected to horizontal deecting plates 62, 63, B4 and 65 of the tubes 32 and 33, respectively.

In this manner, the saw-tooth voltages act through the vertical and horizontal amplifiers to synchronously scan electron beams of the tubes 32 and 33 radially, synchronously with the trans- T55 -rmissionroiipulsesrbyithe antennaaii I. flheidirec- :zticnrofltheserradialtsweepsiisi determined and continuously f varied :accordinggtofthe angular; position father-antennae i le about.;v ac vertical axis. The

f otaryftransformenl' according toftheslowly..` osllatingaimovementsgof theantenna yI I :..abouta orizontal axis.

rfsinceztheisweeps' begin synchronously withVV the determined by ithezfrequencyfof tthe s synchronizer :20

Lw38. I`-he amplitude .ofszthe voltages is: determined :by the-elevation angle -iofnthe antenna I I. lif'his is i agccomplishect` 'by controlling :the amplitude; of the stereoscopic saw-toothvoltagesnby the output of can observer :sees: ai threeedimensionalfl p'cturerby "fzviewing,tthenrepresentationsseparately-iwith-his `.-:individualeeyes.

, engtlrpteach radial-sweep is; determined; bylthea 5 transmissionipf radiant: energy pulses-athen; posi-.- f

In order. toSenabIesthe:.observerrtoF viewizlthese stereoscopici representations; independentlyzlpo- .larizing. screens 'II andiSI2:arer positioned:in:front ofxthe screens 35..andvi36ixand arrangedftofpolarize ithe light .therefrom diferent iiirecti'ons. iifl'he polarized representations'may; if;Sd'esired; be'sf-ocused by Vlenses 73.,.and *Iii toscombinenthe'mepreisentations. Byusing projection 4.type :cathode :ray

tubes :the stereoscopic representationsmayhe:io-

icused, cna ,screenrsuchzas' :that shown: yatti 5 :fin

enig.. 2. As xshown; in `.thisigure;;tubesf32 5and533 are: arranged .soi the` arepresentationsion 'their rre- 1 spective ,screens Varewsuperimposed bygtheg'lenses land ilon thefscreen 15. The effector-polarizing-screens-V II andff'IZ enable..Y the .obserslen-by viewing the screen 5.through;:p olarizeddiscsaflS and 11; to View 1the:stereoscopic'representations independently with his eyes 'I8 and;l9.

slt-desired; transparent films' 8 Landf Zrfcontaining ystereoscopic 4images,"'mapsvor` loutlinesrnieathe ground area kvo verfwhiclrtheK objects arefiocated -..afsecondiwin-ding ofrthe rotary transformera-in ac-.3lfmay :beplaced over ithefscreens 35 .and 3 6. FBy j adjusting :theesensitivity Iof fthej tubes @fands-33,

t, icordancei .withftlfle` sineiofgthe elevationangle of the antenna :I I.

:Theleads '.61 and-68 arefconnected to horizontal ..,arnpliiiersrd9and.I5Il and-factito shiitpthe cathode ray beams of the tubesf32'zand33 horizontally in:;t30`

oppositedirectionsinaccordance with the arnplitudeiof `the stereoscopic saw-tooth voltages. Sincefthese 4voltages are produced synchronously with the transmission of radiated pulses, the elecn shiftedvfhorizontally after. the radiation of each L. pulse so traces produced-bythe reception of re- .ilectednergy are stereoscopically displaced in accordance with the distance of the objects relative-toa-reference plane or the ground. Y

The stereoscopic control 66 may include a balanced ampliiier-having variable controls actuated by. knobs 69 and 'I0 to vary the direct current level and ,thaamplicationfactor. Since the normal displacement between `the representations on. tubes 32 and 33 is determined by therdirect cur- .rent. level ofthe leads 61- and 68, knob Ell-'may be :adjusted to vary .the normal displacementof objects atground level, that is, at the level of the reference plane. .Adjustment of the amplification oi ,the saw-tooth voltageby turning knob 'I5 con ...trois the amplitude of :the stereoscopic displacement. .This amplitude isa scale factor which de- ;.termines v4the contrast for objects of different heights. and maybe varied according to the cievices of individual apparatus.

.Aidisplacement ofthe electron beams based solely upon .the time interval of transmitted and received pulses would displace the stereoscopic representation ofthe objects according to their range .fromthe antenna II. Y However, since the amplitude of the saw-tooth voltages from the stereoscopic` control 56 is governed by the posi- `tion of the antenna II in elevation, the stereo- `scopic displacement corresponds to the range of the objects multiplied by the sine of the elevation angle whichis, ofcourse .the altitude of the objects.

The radio locator thus produces stereoscopically displaced representations of the goniometric position of .objects Within the scanned area which appear on the screens 35 and35 of the cathode ray tubes '32 and :33. The stereoscopic displacement V`corresponds to the altitude of the objects, that is, the'distance from a reference .planewhereupon suicient background i light :smay f be gtproiected screens "15. These `representations;of theeground arearare thus Vsuperimposed upon representations oithe objects andthe two pairsxof.representations i are combined in afmannerisuch that'the observer .mayview one of-each oisaidpairsei representatronbeams in-,tubestZ` andf33 are continuously;35 .tions separately with his individualeyes.

The locator described, mayfbe.; of any? tiypegcto produce the desired stereoscopic representations. -IIn the apparat-us shewnzand described herein-a hemisphericalportion of spacehaving itsI-.base-fon 0. the groundvis'scanned. Obviously,ftheradiodocator may-scan any. selected-portionof-spacer and have any reference. plane as f-affbase Without-.de-

e partingv from theinvention.

. ijectswover a'vselected ground xarea,A refereneez may lorv a; morerdetailed: description of suitablef apparatus forproducing stereoscopiczimagespf obbefhad -to Ycopending application ,SerialzzNo 498,605 for-stereoscopic image producing apparatus, filedlin the names of--W.,A.#Ayres .and- E;v C.

Streeter, Jr.

rThe. present invention concerns-primarilythe provision of a stereoscopic representationiwhich -may be combined with the; stereoscopic reprev sentation of `an object-to direct an instrumentztoward` a selected object. The'embodiment of. the invention illustrated and described in this'. application concerns the direction ofi` a communication `beam-toward a selected aircraft or other; object over .e1-predetermined portionnof fspace.

- However, it will be apparent that the apparatus Y `could be used to produce a stereoscopic representures.

a gear 91 to drive through gearing 98, which rotates the bracket 94. The elevation position of the antenna 9| is likewise adjustable as by hand crank 99 which drives through a pinion |0| meshing with a sector |02 on the shaft 93. A suitable communication transmitter |03 and receiver |04 are connected to the antenna 9| through wave guides and |06 for the transmission and reception of radio energy.

Since it is desired to provide a stereoscopic representation of the position of the communication beam pattern of the antenna 9| relative to the stereoscopic representations of objects as produced by the radio locator heretofore described, it is first necessary to generate a picture representation of the communication beam. For this purpose a picture generator tube the design of which is known to those skilled in the art and conforms generally to conventional cathode ray tubes, has a target ||2 adapted to be scanned by an electron beam.

The three-dimensional eiect produced by stereoscopic representations depends upon the displacement of corresponding portions in two pic- It has been found that a desirable picture for a directional characteristic of an instrument should have an outline corresponding to the outline of the characteristic but include suitable indicia, such as the cross-hatching shown on the target 2, to provide reference points on the picture Which may be used by the observer in viewing the stereoscopic representations to produce a three-dimensional picture. The lines of the target I2 are preferably formed of insulating material, whereas the unmarked portions are of conducting material.

The cathode ray beam of the tube I is spirally scanned over the target by two phase voltages from a generator ||4, the amplitude of which is controlled by a saw-tooth generator ||5. One phase of the generator ||4 is connected to a modulator i 6 where it is combined with the output of the saw-tooth generator ||5 A similar modulator I|1 is connected to the other phase of the generator ||4 and also combines the generated voltage with the saw-tooth output to produce a voltage varying in amplitude in accordance with the output of the saw-tooth voltage generator ||4 The voltages of modulators 6 and ||1 are connected by leads ||8 and ||9 through 360 phase Shifters i2| and |22 to horizontal and vertical amplifiers |23 and |24.

The horizontal amplier is connected as by leads |25 and |26 to horizontal deflecting plates |21 and |28 of the tube Similarly, the output of the vertical amplifier |24 is connected by leads |29 and |3| to vertical deflecting plates |32 and |33 of the tube Since these voltages, applied to the horizontal and vertical plates of the tube are displaced by 90 and varied in amplitude according to the output of the saw-tooth generator ||5, the electron beam of the tube I|| is spirally scanned over the face of the tube at a frequency determined by the saw-tooth generator H5. As the electron beam scans over conducting portions of the target H2, current flows through the tube which produces a voltage across resistor |35 corresponding to the picture formed by the target ||2. This voltage is connected by lead |36 to intensity control grids |31 and |38 of cathode ray tubes |39 and |4| to control the electron beams of these tubes.

The outputs of the modulators H6 and l'ii are also connected by leads |43 and |44 across specially designed potentiometers |45 and |46. A

portion of this voltage as determined by the position of potentiometer sliders |41 and |48, is supplied by leads |49 and |5| to horizontal amplifiers |53 and |54 of the tubes |39 and |4| and also to vertical ampliers |55 and |56 of the tubes |39 and |4|. Horizontal ampliers |53 and |54 are connected to horizontal deecting plates |6I, |62 and |63, |64 of the tubes |39 and |4|, respectively. Likewise, the outputs of vertical amplifiers |55 and |56 are connected to vertical deflecting plates |65, |66 and |61, |68 of the tubes |39 and |4|, respectively.

By this arrangement, the electron beams of the tubes |39 and |4| are scanned spirally synchronously with scanning of the electron beam of the tube but the area of screens |69 and |1| of the tubes |39 and |4| which is scanned, varies according to the position of potentiometer sliders |41 and |48.

Since the control grids |31 and |38 of the display tubes |39 and 4| are controlled according to the output of the picture generator tube representations appear on the screens |69 and |1| corresponding to the target 2 which, as has already been described, is a picture of the communication beam pattern, of the antenna 9 The size of these representations varies according to the areas of screens |69 and |1| which are scanned, as determined by the position of potentiometer sliders |41 and 48.

In order that the representations of the communication beam appearing on the screens |69 and |1| will correspond in direction to the azimuth direction of the antenna 9|, a phase displacement is introduced between the synchronously scanning beams of the picture generating tube and the display tubes I 39 and |4| corresponding to the azimuth angular position of the antenna 9|. This phase displacement is accomplished by adjustingv phase shifters |2| and |22 in the circuit of the picture generating tube according to movements of the antenna 9| in azimuth. For this purpose a shaft |13 is driven by gear |14 that is rotated by pinion |15 and shaft |16 which is in turn driven by gear |11 meshing with pinion 96.

As the operator adjusts crank to position the antenna 9| in azimuth, phase Shifters I2| and 22 adjust the phase relation of the spiral scanning voltages applied to the picture generating tube according to the azimuth angular position of the antenna 9|. Obviously, either the scanning beam of the picture generating tube Ill or scanning beams of the display tubes |39 and |4| may be shifted to produce the same result. It is only necessary that phase displacement be introduced corresponding to the azimuth angular position or displacement of the directional instrument.

The apparatus thus far described provides a pair of representations of the communication beam which appear on screens |69 and |1| of the cathode ray display tubes 39 and I 4| The representations are positioned on the screens in accordance with the azimuth angular position of the antenna 9|. It is now necessary to introduce stereoscopic displacement between the two representations of the directional characteristic in order to provide a three-dimensional picture for the observer.

The stereoscopic bias could be obtained by producing a Voltage corresponding to the elevation angle of the antenna 9|. Thus, by introducing displacement between the two representations corresponding to the distance of various portionsfoffthe-beamopatternifromaheground;;ap-.f propriate stereoscopic representations `Avi/'cn'slldA4 ei; obtainedil. Howeverayin `the embodiment-l' offrth inventioushown; iinf'the idrawingsitf ris zcontema 1 plated thatcthelgroundaarea:overiwhichitheispacei;5 menta... As 'thewcommunication `beam is movedf upward infelevationf the'amplitude offthe sawis iscanned would.have'f-.asdiameteri. considerablye4 inrexcess ofthe maximumf'altitude. .y Forfexample,'.1V the locatornmigihtxbexefctive eover. amaretti-havn* ing :fa radius fof approximatelyslzmiles whereas?.

windings; I |9| of potentiometer.`vv |S5"'.arranged r withinfthe rstportionof movement ofv kthe slider |86, and a solid conductor |92 adaptedtoiengage theslider lfduring theremainder-ofxits move-` tooth-generatorfis* variedaccording to the elevationvangle.; Asthe -amplitude is increased; the Various-portions of the :representa-tions on the it would :not be rnecessanygrto communicatefwithefloscreens-ISQ-and-MI'H areshifted-horizontallyacaircraft ataaltitude'sf inexcessJ pfel 0 imllesn..

It` will i fbes-,apparentz-A thereforeffthatg ithe; repre f sentation.-l of-i theecommunieation beam -mustwzbe s? capable `of proj ecting.=a.disg tance iat-f lo,Weabt-nudes'.-il corresponding to the iradius which the locator is effective.' Iny-thegexample vset'. forth this would be100'..mles-.m Cinq-thef'--otl-.ier hand, when.` .the Acommunicatinggbeam isvdirected upwardly; it :is fonlyl1 necessary gtofrepresei'it .,tl1atv .r

miles. Obviously the stereoscopic definition-iis improved if the 'scales ranges-fiumi only@ to A10 miles ratherv thanffromr to lamiles-which l would be the altitude.of, a.l(l0.mileibeampointing,A directly upward.Y

It `.is desirable. thereforewtor'limit theY stereos--` scopic displacementito. an,..a1nount corresponding, toa maximum. altitude over-rwhich theapparatus is to .be effective.. If .thisdsdoneitfis' desirable..

to fore'shortenf.thecommunication-:beam so it ..-30f=CreaseS,.the'utputs of .mOdlilaOIS l l5 and H1 are multiplied bythe cosine ofthe elevation angle,` whereupon the amplitudes of voltages. IM and terminates at a.se1cted..altitude,f which preferaably is the same as the maximum...altitude` Thus, the, representation lof .l th"e .communication.. beamv should 'becomeshorter `as th'ef elevation .angleincreases.

Iriorder to stereoscopioallyl ,displace the. repre-1 sentations Ylof 'the directional ,Scharacteristic ,Tapi-fpearing onthe screens `l 69, and .l 'I ,fastereoscopic f control I8 I is actuated .bythesaW-tooth genera@ polarity to the horizontal amplifiers .|53`.an d ,1541i As the radius oi thespir'alfscan of. the.,tubesllal andi |4|"changes', thbeamsare .shiftedihoriezontally an amount ,depending Alyson-. ,t1ie. ampli,`

tude of the stereoscopic controljvoltages supplied 45 Greater spacingpf the representationsare re1- quired to providev a three-dimensional pictureatf.

long ranges than 'at ,shortiranges Theinventin. 50

contemplates an arrangement for adjusting ,autor matically -ltheispacing"oftlie' representations as' the'elevation'angle is changedf the',isp'aei'ng'jin' creasing within predetermined limitsas'jtl'ieelef-- vation angle increases. zero elevation, that'is;Y when, the "communication beamilis directed-;horizontally; the stereoscopic. control-voltages-should Lbeta minimum: To tac.- complish this; -theioutput `off-the saw-tooth 'geniposition: off the: slider--| 863Lz The maximurnfoutpuv of "the saw-tooth--generator |'5 `corresponds to the lina'xi'rn'um stereoscopic 'displacement desired? Which'iis .determined-b` thennaximurrraltitudeat' thelfapparatusfisto #b eibtiver 70 Since the stere'oscopic :displacement r-fis'l limited to aigivenialtitude;the.=stereoscopicldisplacements voltages@ increase. fonlyI-'duringeitheefist;-lportionlof movement of the communication'fbeaminiele# vationz;V Thisfzis .saccomplishedisbyehaving the 75 When'the 'antenna jisljaty 55 cordingto'theldistance of corresponding portions Y' of thewcommunication fbeamppatternabove the ground;i

Potentiometer-sliders |4l-and lrarealso ff-theyarea govern 15driven by shaft-|81 through gearing Y|95 and |96 v accordingto the elevationangle of'the antenna The sliders l'l andlll'are pivotedat one 9|. endof the linear .windings |45 andlll andare so arranged-thattheLvoltage of the-sliders is de-v portion- =of .itfwhichi extends to an v a1titude.of.,f10 20 ncreased as the .elevation angle uincreases.4

cosine of the elevationangle.

elevation angles.v As theelevation angle inf- |48 which are supplied to the Ahorizontal anclvertical ampliers of the display tubes |39 and UH... 35 reduce the diameter of the spiralscanningmovethe area of the screenslES and I'll scanned by.. tor l l5 to supplyjsawftoothyoltages oopposite 402th@ beams .is reduced as a function of thecosine of the elevation angle. This shortens the representations ofthe beam pattern appearingon screens |69 and `I'll' as the Velevatiomangle irlcreases.

quired for the longer ones. Therefore, the stereoscopic control voltages from the stereoscopic con.- trol |8| horizontally displace thervarious portions of the `relciresentations. being displacedhorizontally according to the distance of corresponding.

lli |Lv These representations are continuously positoned 'in accordance with theV azimuth position of theV antenna. As the antenna moves upwardlyl in elevation, Various portions of the two representation-s are displaced horizontally in accordance with the distance of @corresponding portions of the communication; beam pattern from the ground.- When the ends of the representationsV have been displaced inaccordance with the maximum altitude ,atlwhich the apparatus is to be eective, the stereoscopic displacement remains constant ibut the representations are oreshoi't--v ened as the elevation angle increases.

representations are foreshortened, the stereoscopic displacement of the ends continues toV cor--y respond tothe,` maximum altitude, so when the antenna- 9| -is pointed vdirectly upward and the This-- arrangement `provides a multiplier which multiplies. the output of modulators |16 and! Il' bythe.

` However, the same .time is required toproducethe shorter representations as was re- As the..

representations of *the directional Vcharacteristic 1l are merely spots on the screens |69 and I 'I I these spots are displaced in accordance with the maximum altitude.

The stereoscopic control I8I has knobs 2 II and 2I2 adapted to control the direct current voltage level and the amplification of the saw-tooth voltages supplied by leads |82 and |83 to the horizontal amplier. The direct current voltage level may be adjusted by knob 2I| to determine the normal displacement of the two representations on tubes |39 and II'II to place the origin of the beam representations at any desired altitude. Adjustment of knob 2| 2 controls the amplitude of the saw-tooth voltage supplied to the horizontal deecting plates which determines the depth contrast for diierent portions of the communication beam representations.

In order to enable the observer to independently view the stereoscopic representations of the communication beam pattern appearing on screen-s |69 and I'II, polarizing screens 20| and 292 are positioned in front of the screens |69 and III. Also, the stereoscopic representations may be focused as by lenses 263 and 2M at any desired point.` By using projection type cathode ray tubes as shown in the drawing, and arranging them as shown in Fig. 2, the stereoscopic representations of the directional characteristic may be superimposed upon the representations of the objects and the ground area on screen 15. Thus, the stereoscopic representations of the objects over a selected area appear on the screen 'l5 and stereoscopic representations of the directional characteristic of antenna 9| are combined therewith in a manner such that an observer may separately view one of each of the pairs of rep resentations with his individual eyes, hereupon the representations are fused in his brain to form a three-dimensional picture.

The three-dimensional picture will show the position of the communication beam relative to the various objects within the portion of space scanned by the locator. The operator may then adjust the antenna 9| in azimuth and elevation to direct the communication toward a selected one of the objects appearing on the screen l5. As the antenna is moved the stereoscopic representations of the beam are adjusted so the threedimensional picture shows, at all times, the position of the communication beam and indicates when it is being directed at a selected object.

In order to accurately direct the communication beam toward a selected object, another indicator in the form of a cathode ray tube 208 may be employed. The intensity control grid 201 of cathode ray tube 206 is controlled by the output of a radio receiver 208 that is connected by wave guide |06 to the antenna 9|. Antenna 9| is continuously rotated or spun by a motor 209 which is energized from a source 2| I, whereupon the beam pattern of the antenna generates a cone about spin axis 2|?. Energy radiated by the locator antenna II may be reflected by an object to antenna 9|. As the antenna 9| spins and conically scans its beam pattern about the spin axis 2| 2, the envelope of reected energy supplied to the receiver 208 varies in accordance with the displacement of a selected object relative to the axis 2|2.

The phase and amplitude of the variations in this envelope may be compared with voltages from a two-phase generator 2I3 by azimuth and elevation phase detectors 2|4 and 2|5 to produce output voltages corresponding to the azimuth and 12 elevation displacement of the axis 2 I2 relative to the selected object.

These voltages may be supplied by leads 2I6 and 2I'I to horizontal and vertical amplifiers 2|8 and 2| 9 which are connected to horizontal and vertical deflecting plates 22|, 222, 223 and 224 of the tube 206, respectively. The voltage from phase detectors 2 I4 and 2I5 will thus act through ampliiiers 2|8 and 2I9 to displace the electron beam of the tube 206 anl amount and in a direction corresponding to the amplitude and phase relation of the envelope of received energy. As the reception of reflected energy actuates grid 201 to permit passage of electrons a trace will appear on the screen of the tube 206 to indicate the displacement of the spin axis 2I2 of the antenna relative to a selected object.

If necessary, suitable compensation may be provided at the wave guides |05 and |06 to alternately connect the antenna 9| to the transmitter |03 and receivers |04 and 208.

As stated at the outset of this description, the

Vspecific embodiment of the invention shown in the drawing produces stereoscopic representations of a communication beam pattern of an antenna. However, it should be understood that the invention may be used to provide stereoscopic representations of the directional characteristic of any instrument. Furthermore, any geometric plane may be substituted for the ground plane as a reference from which to measure the distance for the proper stereoscopic bias.

The stereoscopic representation of the directional characteristic of an instrument according to this invention produced, may be combined With stereoscopic representations of objects over a selected area as well as with representations of the area. These combined representations form composite stereoscopic representations. One of each of the pairs of representations produced is polarized or otherwise arranged to be viewed separately by one of the eyes of an observer, while the other representation of each of said pairs is polarized or arranged to be viewed by the second eye of the observer.

Since many changes could be made in the above construction and many apparently widely diierent embodiments of this invention could be made Without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. stereoscopic apparatus comprising a locator, a display device actuated by said locator for producing a stereoscopic representation of an object, an instrument having a directional characteristic, and means responsive to the position of said instrument for combining a stereoscopic representation of said directional characteristic with the stereoscopic representation of said object.

2. stereoscopic apparatus comprising a locator for producing a stereoscopic representation of objects in a selected portion of space, an instrument having a directional characteristic, means responsive to the position of said instrument for producing a stereoscopic representation of said directional characteristic, and a display device actuated by said locator and said means for combining said stereoscopic representations to show the position of said directional characteristic relative to said objects.

3. stereoscopic apparatus comprising a locator 13T?. fonproducing-aapairfzpfsterecscopicallpglisplaoed;l representations: of 1an objectif-an instrument elia-ys l f insta-directional cha-racteristic,3meansfresponsive@v to'itherposition -of saidginstrumentfforproducingf a fpairso stereoscopicallmrdisplacednzrepresenta `said dir tionalicharacteristics, meanstres-ponsive tionspfisa1dzdirectionahcharacteristic;rand as disf playidevicezgfor combiningcsaidzpai-rsot represernP tations rinra smannei-wherebi'c fone: otiezaclnotf'isaida e ;;:Appairatus:forproducing astoreoscopicirep-i.r i

resentation of a-,idirectional,characteristics ofianzl instrument comprising a display devicefforzproeducing;a.-=;pair of stereoscopic lrepresentations of to fthe; angulanposition of: said finstrumentrfwithf Y- in -vonezportion Ipf yits'srangeof movementforcaus-ting; sterieoscopicy;displacement of iat :least ionen-toile said; `representationsand means "responsive to saidf 10' cangula-n positionf-of'f,tsaid c instrument Within;v ai.

secondgportion. off: its; :range of 4fmovement fon changing theilengthrot saidrepresentationsfa,

111;; Apparatusrforfproducing a stereoscopic;rep-f.:V resentationto ra @directional characteristic .oisans ,15 @instrument comprisingea display device Ifor; prn-c ducingigaf-Qpa i :stereoscopic:irepresentations;-of.: said directional;characteristic;a positioning des vicenactuated by saiidiinstrument :foryadjusting theepositionp-fzsaid representations accordingztof;

zogthecanguhn positionnent said zinstrumentnaboutrf oneeaxisea estereoscopicz controlfresponsivefto tana: gulansp ositionrgofes aid instrument` abouta second. c aidsiiorlica-using stereoscopicvv displacement :oiwat:1 least;ionereofrisaidzrepresentations' accordinggito charactesbic meansriresponswe td thegpositondgg,qtheipositionzfoizsaidzinstrument'aboutsaid second;

ofssadfcol'lfectorfor combining-a 'stereoscopic reps? resentationofisaid directional cir'aracteristicwith th-frepresent'ationsoffsaid:obj'ectsfand anindiii catoru responsive'.` to the reception `of' radiant energy from, an `oloect' andQtlife positionpf I'said collctrfor "indicating-Iliadisplacement "ofl jsaid directional characteristic relatiyelto; aseIe'Gtedi OIOZCCL.;A

axis,:'andnneansxresponsive to, the positionof vsaidff instrument::aboutfsaidgsecond axis; for, changing thelength ofisaid representationsa;r

12,:.1Apparatus -ifon 'producing fx; a zz' stereoscopic;

,30 representation offra directional characteristicpot-1 an einstmnnentf comprising, a ipicture 1 generatonfor f generating signals? correspondinggto a represen-g tation oiesaid directionalcharacteristic;a displays: device; fconnectedL-.toesaid generatore` for fproduce;

resentation A,offindiiectiofnal ,characteristic,ofjann instrumentA 'comprising ga ,display4 :device .for prov..

ducirig Ya :pairlof stereoscopicl representations. of saiddirectional characteristic,and a stereoscopic.

control ,responsive .tol the angular positionpt. said L40 instrument-foncausingstereoscopic displacement, of at least-one. ofssaid-{representations.

'7. 'Apparatus for producing a stereoscopic representation of a1directional',characteristic of an instrument comprising a displayrdevioe for-,m01

ducinga pair uof stereoscopic representationspf .45

said directional characteristic, a positioning de-A vice actuatedbyisaideinstrument. fonadjusting the position-,of--said representations. according to, the.,` angulariposition of said instrument abouteonet-4 axis; .and-lV aistereoscopic controkrespousivetto the e5() angular position of said instrumenta-about:assess ond axisifoncausing stereoscopic `displaceitelentof r.

at least enact-said representationsm 8.LApparatusffor producingastereoscopiarepres sentation of a directional characteristic of an instrument comprising a display device for producing a pair of stereoscopic representations of said directional characteristic, and means responsive to the angular position of said instrument relative to a reference plane for causing stereoscopic displacement of portions of said representations corresponding to the position of corresponding portions of said directional characteristic relative to said plane.

9. Apparatus for producing a stereoscopic representation of a directional characteristic of an instrument comprising a display device for producing a pair of stereoscopic representations of said directional characteristic, a stereoscopic control responsive to the angular position of said instrument for causing stereoscopic displacement of at least one of said representations, and means responsive to said angular position of said instrument for changing the length of said representations.

characteristicsiandaa Lstereoscopic control respon- `sive'itc'therrangulan position; 'oa said vfinstrllnient :i

forcontrolling-isai'd; display devicer to-nstereoex scopicaliydisplace;said two representations;

1 lai-Apparatus for producing i, a A stereoscopic:` representation -ofzza r directional characteristic f of andnstrumentgcomprising apicture Vgenerator for;v generating signals ccorresponding -.to 1a; represene. i tationfiofisaidfdirectional characteristic, a display;4V

, device connected to' sai-d -sgenerator fornproducine' a pairanfnepresenftations :ofzsaid 'directional'chare acteristicic.phaseeshifting means:vv responsive tof thefangularfposition :of isaid instrument about a first axis for rotating said representations; and:l

a stereoseopicz'control fresponsive V:to fthe* angular positionof sfsaid'; instru-meritv about 4a second axis foricontrclling;saidrdisplay,:devicestofstreoscopi-e callin-displace'. said two` representations;`

14n-Apparatus@ fon producing:` a stereoscopic,

.representation-110i t 1a directional' .characteristic of:

an instrument comprising a picture generator -for generating signals corresponding to a representation of said directional characteristic, a display device connected to said generator for producing a pair of representations of said directional characteristic, and means responsive to the angular position of said instrument for controlling said display device to adjust the length of said two representations.

15. Apparatus for producing a stereoscopic representation of a directional characteristic of an instrument comprising a picture generator for generating signals corresponding to a representation of said directional characteristic, a display device connected to said generator for producing a pair of representations of said directional characteristic, phase-shifting means responsive to the angular position of said instrument about a first axis for rotating said representations, and means responsive to the angular position of said instrument about a second aXis for controlling said display device to adjust the length of said two representations.

16. Apparatus for producing a stereoscopic representation of a directional characteristic of an instrument comprising a picture generator for generating signals corresponding to a representation of said directional characteristic, a display device connected to said generator for producing a pair of representations of said directional characteristic, a stereoscopic control responsive to the angular position of said instrument for controlling said display device to stereoscopically displace said two representations, and means responsive to said angular position of said instrument for controlling said display device to adjust the length of said representations.

17. Apparatus for producing a stereoscopic representation of a directional characteristic of an instrument comprising a picture generator for generating signals corresponding to a representation of said directional characteristic, a display device connected to said generator for producing a pair of representations of said directional characteristic, phase-shifting means responsive to the angular position of said instrument about a iirst axis for rotating said representations, a stereoscopic control responsive to the angular position of said instrument about a second axis for controlling said display device to stereoscopically displace said two representations, and means responsive to the angular position of said instrument about said axis for controlling said display device to adjust the length of said representations.

18, Apparatus for producing a representation oi the directional characteristic of an instrument comprising a picture of said directional characteristic, a display device, means for synchronously scanning said picture and said display device for producing a representation of said directional characteristic on said display device, and a phase shifter responsive to lthe angular position of said instrument for adjusting said means to control the phase displacement between the scanning of said picture and the scanning of said display device, thereby positioning said representation according to the angular position of said instrument.

19. Apparatus for producing a representation of the directional characteristic of an instrument comprising a picture generator tube for generating signals corresponding to a representation of said directional characteristic, a display tube, a Synchronizer, means actuated by said synchronizer forvsynchronously scanning said l tubes to cause said display tube to produce a representation of said directional characteristic, and a phase shifter responsive to the angular position of said instrument for controlling the angular position of the representation of said directional characteristic on said display tube according to the angular position of said instrument.

20. A method of directing an instrument toward an object, which comprises the steps of producing a stereoscopic representation of the location of the object, producing a stereoscopic representation of the location of the directional characteristic of the instrument, combining said representations to form a composite stereoscopic representation showing the position of said directional characteristic relative to said object, and manipulating said instrument to direct the representation of said directional characteristic toward the representation of said object.

21. A method of producing a stereoscopic representation of the directional characteristics of an instrument which comprises the steps of producing a pair of representations of said directional characteristics, stereoscopically displacing said representations according to the angular position of said instrument, and changing the length of said representations according to said angular position of said instrument.

22. A method of producing a stereoscopic representation of the directional characteristics of an instrument which comprises the steps of producing a pair of representations of said directional characteristics, stereoscopically displacing said representations according to the angular l position of said instrument within one portion of its range of movement, and changing the length of said representations according to said angular position of said instrument within a second portion of its range and movement.

WALDEMAR. A. AYRES.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,301,254 Carnahan Nov. 10, 1942 2,107,464 Zworykin Feb. 8, 1938 934,916 Von Hofel Sept. 21, 1909 1,514,948 Barr et al Nov. 11, 1924 1,864,899 French June 28, 1932 1,987,765 Wandersleb Jan. 15, 1935 

